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Re: Sonderman Makes Sparks



---------- Forwarded message ----------
Date: Tue, 7 Oct 1997 19:08:59 -0500
From: "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Sonderman Makes Sparks 

To: Ed

Sounds like your reactor may be saturating and hitting very high impulse
current peaks which can produce the loud pops you refer to.  We have noted
this on larger coils if the cross sectional area of the reactor is not
sufficient to deal with the high peaks -- in a 5-6 kva coil the peaks are
upwards of 70 kilowatts for very short time durations.  These high current
peaks fire across the gap instead of providing controlled current to
recharge the HV caps in the tank circuit.  Hope this data helps and glad to
hear you are sparkin' again.

DR.RESONANCE-at-next-wave-dot-net


----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Sonderman Makes Sparks 
> Date: Tuesday,October 07,1997 12:43 PM
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Tue, 7 Oct 1997 12:27:26 -0400 (EDT)
> From: Esondrmn-at-aol-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Sonderman Makes Sparks
> 
> I did a lot of testing last night and finally got some reasonable
results.
>  Not great but better than I have got for a long time.  I will list all
of
> the test results here and maybe someone can give me some more ideas.  My
goal
> was to find combinations of primary set up that would allow the maximum
input
> power without firing the capacitor safety gap.  The main H.V. safety gap
> never did fire so when I say the gap fired, it is the cap safety gap I am
> referring to.  It was set at 5/8".  I was using a 40" toroid with a wire
> laying on one side pointing to a grounded wire about 3 feet away for most
of
> these tests.  The primary was tapped at 11.75 turns which is the best
tune I
> found from previous tests.
> 
> Test set up # 1:  Took the welder out of the circuit and used resistive
> ballast only.  No resistors in series with the H. V. leads.  With R = 22
> ohms, I could go to full variac voltage, smooth control and no safety gap
> firing.  Primary current was 6 A and primary voltage (into the pig, 60:1
> turns ratio) was 160 V.  I decreased the ballast resistance until I got
to
> 7.0 ohms, the primary I = 16 A, primary E = 200 volts.  Now I was getting
> popping in the rotary.  I don't know how else to describe it.  I hear
pops
> (not real loud like the safety gap makes) and see light flashes coming
out of
> the rotary box.  I actually had this problem back with the old
configuration
> that used to make the 80" sparks.  Since it sounds like a symptom of a
> problem that I don't want, I put the static gap back in series with the
> rotary.  Popping went away, primary I dropped to 14 A. Decreased R to 4.8
> ohms, I = 14A, E = 225 V.  Works ok still.  Decreased R to 4.0 ohms and
the
> popping in the rotary comes back.  Is this some kind of kick back
condition?
> 
> Test set up # 2.  Again using only resistive ballast and adding series
> resistors in each H.V. feed line (near the pig, on the safety gap board).
 I
> used two 300 ohm, 50 W resistors in series on each side - 600 ohms total
in
> each leg.  At R = 4.0 ohms, primary current is 14A, E = 225V.  Gap firing
is
> a little erratic, discharge sparks are hitting the ground wire, overall
> performance not very good.  Decreased R to 3.3 ohms and now the popping
is
> back in the rotary.
> 
> Test set up # 3.  Same set up as #2 only the welder has been placed back
in
> series with the resistive ballast.  With R = 22 ohms, welder set on
minimum,
> I = 6A, E = 180V, the secondary discharges are much hotter and louder
than in
> the previous tests - with no inductance (welder) in the primary circuit.
>  Changed welder setting to maximum (230 A setting) and performance is
worse.
>  Set welder back to minimum. Decreased R to 4.0 ohms and performance is
good,
> getting 44" discharges, I = 15A, E = 245V.  Decreased R to 3.3 ohms and
the
> safety gap starts firing.  So far, the best performance is with the
welder in
> the circuit and when the series resistance gets too low, the cap safety
gap
> fires.  I would think this indicates I am getting 60 hz resonance now and
it
> appears I want some for best performance but not so much that the safety
gap
> fires.
> 
> Now I set the welder back to maximum and performance is better.  It seems
> when R is high (10 to 20 ohms) the ballast inductance needs to be high. 
When
> R is low (3 to 5 ohms) the ballast inductance needs to be low - for best
> performance.
> 
> With the welder set on maximum and R = 4.0 ohms, I started to slowly
increase
> the rotary speed.  I got up to maybe 400 to 500 BPS, performance got much
> better and the safety gap started firing again.  I backed R off to 4.8
ohms
> and now get 57" sparks and an occasional firing of the safety gap.
> 
> Well, that's it.  I am getting reasonable performance but not what I used
to
> get.  The coil is working well once I get the right combination of
> everything.  Now, what do I do next?  I want to get the primary current
up to
> 30 amps where I used to be able to run.  15A at 245V is about 3.7kva, I
> obviously want to find some combination that will allow me to put in as
much
> power as I have available which is probalby 7 to 8 kva.  Is it possible
that
> this 6" coil system just won't accept that much power?
> 
> Maybe I need to loosen up the coupling some more.  Now the lowest turn on
the
> secondary is about an inch or two above the lowest turn on the primary. 
I am
> using a saucer shapped primary wound at 30 degrees.  If I am not getting
> splitting on the secondary, and I don't see any, maybe I could tighten up
the
> coupling?
> 
> Now I can't believe how lucky I was when I originally built this system.
>  With a lot of help from Richard Quick and a lucky selection of
components
> and layout, I once got 80" sparks.  I wonder if it will happen again.
> 
> Comments welcome, please.
> 
> Thanks, Ed Sonderman